As the background art of this technical field, there is JP-A-2013-24546 (PTL 1). In PTL 1, it is disclosed as an object “that an object is to obtain an air conditioner management system which can realize management of an air conditioner with low cast, and does not have an influence in security on a management system which refers to an air conditioning system of centrally managing a plurality of air conditioners”. In addition, in PTL 1, it is disclosed as means for solving the problem, “that an air conditioner management system according to this invention includes first communication means for communicating between one or a plurality of air-conditioning units which are configured by at least one indoor machine and one outdoor machine, and a centralized controller, and for transmitting information of the air-conditioning unit to the centralized controller; second communication means for performing communication between the centralized controller and communication equipment, and for transmitting the information of the air-conditioning unit transmitted to the centralized controller, to the communication equipment; and third communication means for transmitting the information transmitted to communication equipment, to an individual information management server that manages pieces of information of the air-conditioning units”.